Ambrose, St. Bishop of Milan

333-397

He is called the " Father of Christian Hymnology" and was canonized after his death. He regulated the church chants by a code of his own and founded the Ambrosian chant, a particular method of saying and singing the church service, which was used until the year 600 and was succeeded by the Gregorian chant. He also introduced antiphonal and congregational singing.